Many factors, including environmental responsibility efforts and modern environmental regulations on diesel engine exhaust emissions have reduced the allowable acceptable levels of certain pollutants that enter the atmosphere following the combustion of fossil fuels. Increasingly more stringent emission standards may require greater control over either or both the combustion of fuel and post combustion treatment of the exhaust. For example, the allowable levels of nitrogen oxides (NOx) and particulate matter have been greatly reduced over the last several years. To address, among other issues, environmental concerns, many diesel engines now have an exhaust gas recirculation (EGR) system that directs some exhaust gas from an exhaust system of the diesel engine into an air intake of the diesel engine. It has been found that lower temperature EGR reduces NOx level more effectively than warmer EGR, thus, many diesel engines have an EGR cooler within the EGR system to lower a temperature of the exhaust gas within the EGR system. Many of the EGR coolers utilize engine coolant as a cooling fluid, however, this limits temperature reduction of the exhaust gas passing through the EGR cooler.
Therefore, a need exists for an EGR cooler that does not use engine coolant as the cooling fluid.